At the present time, there are a number of different types of command systems which normally employ simplex systems. However, in order to improve reliability of the command system, it is highly advantageous to utilize a multiplex system, namely, a duplex system.
One example of a brake command system having a multiplex system is described on pages 45-54 of Science of the Electric Train, Vol. 35, No. 4, dated Apr. 1, 1982, by the Electric Train Study Group K.K. This system is shown in FIG. 25 on page 47 of the above publication and this system is reproduced and is shown in FIG. 2 of the subject application which will be explained hereinafter. As shown in FIG. 2, the characters C61-C65, C71, C72, C81, C82, C91, and C92 represent rotating drum controller cam plates linked and operated by a suitable handle (not shown) by the trainman or engineer. The characters S61-S65, S71, S72, S81, S82, S91 and S92 represent cam switches which make or break contact with the above-mentioned cam plates. The number 0 represents the release REL position, while the numbers 1-7 represent the selected normal brake positions. The symbol emerg. is the emergency brake position. The characters SB1-SB3 are the pole connecting lines for the normal brake. The symbol UB is the pole connecting line for the security brake. The symbol EB (+) is the pole connecting line for the positive emergency brake power supply, and the symbol EB (-) is the pole connecting line for the negative emergency brake. In addition, the cross-hatched area on the left side of each cam plate indicates the range in which each corresponding cam switch is ON. It will be appreciated that FIG. 2 shows the state in which the handle (not shown) is at a position in which all cam switches are OFF.
When the handle is operated to the release position and then to the normal brake position, such a position 2 (notch), the cam switches S64 and S65 are OFF, and the normal brake command (1,0,1) is conveyed to the connecting line SB1, SB2, and SB3. In the same way, when the handle is operated at another position, each corresponding cam switch is ON or OFF and each brake command is different.
FIG. 2 shows one example of the existing brake command system in which the brake operating device (not shown) which connects to the pole connecting line is usually energized, and the security brake command system and the emergency brake command system are duplex systems, and each of the corresponding cam switches are connected in parallel. Although the explanation of the figure is omitted, a brake command system in which the normal brake command system is a multiplex system, and a start command system in which the start command system is a multiplex system exists.